stv0g/libwebsockets
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity
libwebsockets/lib/parsers.c
Peter Hinz 56885f3084 introduce win32 build capability 
This adds win32 build compatability to libwebsockets.

The patch is from Peter Hinz, Andy Green has cleaned it up a bit and
possibly broken win32 compatability since I can't test it, so there
may be followup patches.  It compiles fine under Linux after this
patch anyway.

Much of the patch is changing a reserved keyword for Visual C compiler
"this" to "context", but there is no real C99 support in the MSFT
compiler even though it is 2011 so C99 style array declarations
have been mangled back into "ancient C" style.

Some windows-isms are also added like closesocket() but these are
quite localized.  Win32 random is just using C library random() call
at the moment vs Linux /dev/urandom.  canonical hostname detection is
broken in win32 at the moment.

Signed-off-by: Peter Hinz <cerebusrc@gmail.com>
Signed-off-by: Andy Green <andy@warmcat.com>
2011-03-02 22:03:47 +00:00

1404 lines
38 KiB
C
Raw Blame History

/*
* libwebsockets - small server side websockets and web server implementation
*
* Copyright (C) 2010 Andy Green <andy@warmcat.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation:
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301 USA
*/
#include "private-libwebsockets.h"
const struct lws_tokens lws_tokens[WSI_TOKEN_COUNT] = {
/* win32 can't do C99 */
/* [WSI_TOKEN_GET_URI] = */{ "GET ", 4 },
/* [WSI_TOKEN_HOST] = */{ "Host:", 5 },
/* [WSI_TOKEN_CONNECTION] = */{ "Connection:", 11 },
/* [WSI_TOKEN_KEY1] = */{ "Sec-WebSocket-Key1:", 19 },
/* [WSI_TOKEN_KEY2] = */{ "Sec-WebSocket-Key2:", 19 },
/* [WSI_TOKEN_PROTOCOL] = */{ "Sec-WebSocket-Protocol:", 23 },
/* [WSI_TOKEN_UPGRADE] = */{ "Upgrade:", 8 },
/* [WSI_TOKEN_ORIGIN] = */{ "Origin:", 7 },
/* [WSI_TOKEN_DRAFT] = */{ "Sec-WebSocket-Draft:", 20 },
/* [WSI_TOKEN_CHALLENGE] = */{ "\x0d\x0a", 2 },
/* [WSI_TOKEN_KEY] = */{ "Sec-WebSocket-Key:", 18 },
/* [WSI_TOKEN_VERSION] = */{ "Sec-WebSocket-Version:", 22 },
/* [WSI_TOKEN_SWORIGIN]= */{ "Sec-WebSocket-Origin:", 21 },
/* [WSI_TOKEN_EXTENSIONS] = */{ "Sec-WebSocket-Extensions:", 25 },
/* [WSI_TOKEN_ACCEPT] = */{ "Sec-WebSocket-Accept:", 21 },
/* [WSI_TOKEN_NONCE] = */{ "Sec-WebSocket-Nonce:", 20 },
/* [WSI_TOKEN_HTTP] = */{ "HTTP/1.1 ", 9 },
};
int libwebsocket_parse(struct libwebsocket *wsi, unsigned char c)
{
int n;
switch (wsi->parser_state) {
case WSI_TOKEN_GET_URI:
case WSI_TOKEN_HOST:
case WSI_TOKEN_CONNECTION:
case WSI_TOKEN_KEY1:
case WSI_TOKEN_KEY2:
case WSI_TOKEN_PROTOCOL:
case WSI_TOKEN_UPGRADE:
case WSI_TOKEN_ORIGIN:
case WSI_TOKEN_SWORIGIN:
case WSI_TOKEN_DRAFT:
case WSI_TOKEN_CHALLENGE:
case WSI_TOKEN_KEY:
case WSI_TOKEN_VERSION:
case WSI_TOKEN_ACCEPT:
case WSI_TOKEN_NONCE:
case WSI_TOKEN_EXTENSIONS:
case WSI_TOKEN_HTTP:
debug("WSI_TOKEN_(%d) '%c'\n", wsi->parser_state, c);
/* collect into malloc'd buffers */
/* optional space swallow */
if (!wsi->utf8_token[wsi->parser_state].token_len && c == ' ')
break;
/* special case space terminator for get-uri */
if (wsi->parser_state == WSI_TOKEN_GET_URI && c == ' ') {
wsi->utf8_token[wsi->parser_state].token[
wsi->utf8_token[wsi->parser_state].token_len] = '\0';
wsi->parser_state = WSI_TOKEN_SKIPPING;
break;
}
/* allocate appropriate memory */
if (wsi->utf8_token[wsi->parser_state].token_len ==
wsi->current_alloc_len - 1) {
/* need to extend */
wsi->current_alloc_len += LWS_ADDITIONAL_HDR_ALLOC;
if (wsi->current_alloc_len >= LWS_MAX_HEADER_LEN) {
/* it's waaay to much payload, fail it */
strcpy(wsi->utf8_token[wsi->parser_state].token,
"!!! Length exceeded maximum supported !!!");
wsi->parser_state = WSI_TOKEN_SKIPPING;
break;
}
wsi->utf8_token[wsi->parser_state].token =
realloc(wsi->utf8_token[wsi->parser_state].token,
wsi->current_alloc_len);
}
/* bail at EOL */
if (wsi->parser_state != WSI_TOKEN_CHALLENGE && c == '\x0d') {
wsi->utf8_token[wsi->parser_state].token[
wsi->utf8_token[wsi->parser_state].token_len] = '\0';
wsi->parser_state = WSI_TOKEN_SKIPPING_SAW_CR;
break;
}
wsi->utf8_token[wsi->parser_state].token[
wsi->utf8_token[wsi->parser_state].token_len++] = c;
/* per-protocol end of headers management */
if (wsi->parser_state != WSI_TOKEN_CHALLENGE)
break;
/* -76 has no version header ... server */
if (!wsi->utf8_token[WSI_TOKEN_VERSION].token_len &&
wsi->mode != LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY &&
wsi->utf8_token[wsi->parser_state].token_len != 8)
break;
/* -76 has no version header ... client */
if (!wsi->utf8_token[WSI_TOKEN_VERSION].token_len &&
wsi->mode == LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY &&
wsi->utf8_token[wsi->parser_state].token_len != 16)
break;
/* <= 03 has old handshake with version header needs 8 bytes */
if (wsi->utf8_token[WSI_TOKEN_VERSION].token_len &&
atoi(wsi->utf8_token[WSI_TOKEN_VERSION].token) < 4 &&
wsi->utf8_token[wsi->parser_state].token_len != 8)
break;
/* no payload challenge in 01 + */
if (wsi->utf8_token[WSI_TOKEN_VERSION].token_len &&
atoi(wsi->utf8_token[WSI_TOKEN_VERSION].token) > 0) {
wsi->utf8_token[WSI_TOKEN_CHALLENGE].token_len = 0;
free(wsi->utf8_token[WSI_TOKEN_CHALLENGE].token);
wsi->utf8_token[WSI_TOKEN_CHALLENGE].token = NULL;
}
/* For any supported protocol we have enough payload */
debug("Setting WSI_PARSING_COMPLETE\n");
wsi->parser_state = WSI_PARSING_COMPLETE;
break;
/* collecting and checking a name part */
case WSI_TOKEN_NAME_PART:
debug("WSI_TOKEN_NAME_PART '%c'\n", c);
if (wsi->name_buffer_pos == sizeof(wsi->name_buffer) - 1) {
/* name bigger than we can handle, skip until next */
wsi->parser_state = WSI_TOKEN_SKIPPING;
break;
}
wsi->name_buffer[wsi->name_buffer_pos++] = c;
wsi->name_buffer[wsi->name_buffer_pos] = '\0';
for (n = 0; n < WSI_TOKEN_COUNT; n++) {
if (wsi->name_buffer_pos != lws_tokens[n].token_len)
continue;
if (strcmp(lws_tokens[n].token, wsi->name_buffer))
continue;
debug("known hdr '%s'\n", wsi->name_buffer);
wsi->parser_state = WSI_TOKEN_GET_URI + n;
wsi->current_alloc_len = LWS_INITIAL_HDR_ALLOC;
wsi->utf8_token[wsi->parser_state].token =
malloc(wsi->current_alloc_len);
wsi->utf8_token[wsi->parser_state].token_len = 0;
n = WSI_TOKEN_COUNT;
}
/* colon delimiter means we just don't know this name */
if (wsi->parser_state == WSI_TOKEN_NAME_PART && c == ':') {
debug("skipping unknown header '%s'\n",
wsi->name_buffer);
wsi->parser_state = WSI_TOKEN_SKIPPING;
break;
}
if (wsi->parser_state != WSI_TOKEN_CHALLENGE)
break;
/* don't look for payload when it can just be http headers */
if (!wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len) {
/* they're HTTP headers, not websocket upgrade! */
debug("Setting WSI_PARSING_COMPLETE "
"from http headers\n");
wsi->parser_state = WSI_PARSING_COMPLETE;
}
/* 04 version has no packet content after end of hdrs */
if (wsi->utf8_token[WSI_TOKEN_VERSION].token_len &&
atoi(wsi->utf8_token[WSI_TOKEN_VERSION].token) >= 4) {
debug("04 header completed\n");
wsi->parser_state = WSI_PARSING_COMPLETE;
wsi->utf8_token[WSI_TOKEN_CHALLENGE].token_len = 0;
free(wsi->utf8_token[WSI_TOKEN_CHALLENGE].token);
wsi->utf8_token[WSI_TOKEN_CHALLENGE].token = NULL;
}
/* client parser? */
if (wsi->ietf_spec_revision >= 4) {
debug("04 header completed\n");
wsi->parser_state = WSI_PARSING_COMPLETE;
}
break;
/* skipping arg part of a name we didn't recognize */
case WSI_TOKEN_SKIPPING:
debug("WSI_TOKEN_SKIPPING '%c'\n", c);
if (c == '\x0d')
wsi->parser_state = WSI_TOKEN_SKIPPING_SAW_CR;
break;
case WSI_TOKEN_SKIPPING_SAW_CR:
debug("WSI_TOKEN_SKIPPING_SAW_CR '%c'\n", c);
if (c == '\x0a')
wsi->parser_state = WSI_TOKEN_NAME_PART;
else
wsi->parser_state = WSI_TOKEN_SKIPPING;
wsi->name_buffer_pos = 0;
break;
/* we're done, ignore anything else */
case WSI_PARSING_COMPLETE:
debug("WSI_PARSING_COMPLETE '%c'\n", c);
break;
default: /* keep gcc happy */
break;
}
return 0;
}
unsigned char
xor_no_mask(struct libwebsocket *wsi, unsigned char c)
{
return c;
}
unsigned char
xor_mask_04(struct libwebsocket *wsi, unsigned char c)
{
c ^= wsi->masking_key_04[wsi->frame_mask_index++];
if (wsi->frame_mask_index == 20)
wsi->frame_mask_index = 0;
return c;
}
unsigned char
xor_mask_05(struct libwebsocket *wsi, unsigned char c)
{
return c ^ wsi->frame_masking_nonce_04[(wsi->frame_mask_index++) & 3];
}
static int libwebsocket_rx_sm(struct libwebsocket *wsi, unsigned char c)
{
int n;
unsigned char buf[20 + 4];
switch (wsi->lws_rx_parse_state) {
case LWS_RXPS_NEW:
switch (wsi->ietf_spec_revision) {
/* Firefox 4.0b6 likes this as of 30 Oct */
case 0:
if (c == 0xff)
wsi->lws_rx_parse_state = LWS_RXPS_SEEN_76_FF;
if (c == 0) {
wsi->lws_rx_parse_state =
LWS_RXPS_EAT_UNTIL_76_FF;
wsi->rx_user_buffer_head = 0;
}
break;
case 4:
case 5:
case 6:
wsi->all_zero_nonce = 1;
wsi->frame_masking_nonce_04[0] = c;
if (c)
wsi->all_zero_nonce = 0;
wsi->lws_rx_parse_state = LWS_RXPS_04_MASK_NONCE_1;
break;
default:
fprintf(stderr, "libwebsocket_rx_sm doesn't know "
"about spec version %d\n", wsi->ietf_spec_revision);
break;
}
break;
case LWS_RXPS_04_MASK_NONCE_1:
wsi->frame_masking_nonce_04[1] = c;
if (c)
wsi->all_zero_nonce = 0;
wsi->lws_rx_parse_state = LWS_RXPS_04_MASK_NONCE_2;
break;
case LWS_RXPS_04_MASK_NONCE_2:
wsi->frame_masking_nonce_04[2] = c;
if (c)
wsi->all_zero_nonce = 0;
wsi->lws_rx_parse_state = LWS_RXPS_04_MASK_NONCE_3;
break;
case LWS_RXPS_04_MASK_NONCE_3:
wsi->frame_masking_nonce_04[3] = c;
if (c)
wsi->all_zero_nonce = 0;
if (wsi->protocol->owning_server->options &
LWS_SERVER_OPTION_DEFEAT_CLIENT_MASK)
goto post_mask;
if (wsi->ietf_spec_revision > 4)
goto post_sha1;
/*
* we are able to compute the frame key now
* it's a SHA1 of ( frame nonce we were just sent, concatenated
* with the connection masking key we computed at handshake
* time ) -- yeah every frame from the client invokes a SHA1
* for no real reason so much for lightweight.
*/
buf[0] = wsi->frame_masking_nonce_04[0];
buf[1] = wsi->frame_masking_nonce_04[1];
buf[2] = wsi->frame_masking_nonce_04[2];
buf[3] = wsi->frame_masking_nonce_04[3];
memcpy(buf + 4, wsi->masking_key_04, 20);
/*
* wsi->frame_mask_04 will be our recirculating 20-byte XOR key
* for this frame
*/
SHA1((unsigned char *)buf, 4 + 20, wsi->frame_mask_04);
post_sha1:
/*
* start from the zero'th byte in the XOR key buffer since
* this is the start of a frame with a new key
*/
wsi->frame_mask_index = 0;
post_mask:
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_1;
break;
/*
* 04 logical framing from the spec (all this is masked when incoming
* and has to be unmasked)
*
* We ignore the possibility of extension data because we don't
* negotiate any extensions at the moment.
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-------+-+-------------+-------------------------------+
* |F|R|R|R| opcode|R| Payload len | Extended payload length |
* |I|S|S|S| (4) |S| (7) | (16/63) |
* |N|V|V|V| |V| | (if payload len==126/127) |
* | |1|2|3| |4| | |
* +-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - +
* | Extended payload length continued, if payload len == 127 |
* + - - - - - - - - - - - - - - - +-------------------------------+
* | | Extension data |
* +-------------------------------+ - - - - - - - - - - - - - - - +
* : :
* +---------------------------------------------------------------+
* : Application data :
* +---------------------------------------------------------------+
*
* We pass payload through to userland as soon as we get it, ignoring
* FIN. It's up to userland to buffer it up if it wants to see a
* whole unfragmented block of the original size (which may be up to
* 2^63 long!)
*/
case LWS_RXPS_04_FRAME_HDR_1:
/*
* 04 spec defines the opcode like this: (1, 2, and 3 are
* "control frame" opcodes which may not be fragmented or
* have size larger than 126)
*
* frame-opcode =
* %x0 ; continuation frame
* / %x1 ; connection close
* / %x2 ; ping
* / %x3 ; pong
* / %x4 ; text frame
* / %x5 ; binary frame
* / %x6-F ; reserved
*
* FIN (b7)
*/
c = wsi->xor_mask(wsi, c);
if (c & 0x70) {
fprintf(stderr,
"Frame has extensions set illegally 1\n");
/* kill the connection */
return -1;
}
wsi->opcode = c & 0xf;
wsi->final = !!((c >> 7) & 1);
if (wsi->final &&
wsi->opcode == LWS_WS_OPCODE_04__CONTINUATION &&
wsi->rx_packet_length == 0) {
fprintf(stderr,
"Frame starts with final continuation\n");
/* kill the connection */
return -1;
}
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN;
break;
case LWS_RXPS_04_FRAME_HDR_LEN:
c = wsi->xor_mask(wsi, c);
if (c & 0x80) {
fprintf(stderr, "Frame has extensions "
"set illegally 2\n");
/* kill the connection */
return -1;
}
switch (c) {
case 126:
/* control frames are not allowed to have big lengths */
switch (wsi->opcode) {
case LWS_WS_OPCODE_04__CLOSE:
case LWS_WS_OPCODE_04__PING:
case LWS_WS_OPCODE_04__PONG:
fprintf(stderr, "Control frame asking for "
"extended length is illegal\n");
/* kill the connection */
return -1;
default:
break;
}
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_2;
break;
case 127:
/* control frames are not allowed to have big lengths */
switch (wsi->opcode) {
case LWS_WS_OPCODE_04__CLOSE:
case LWS_WS_OPCODE_04__PING:
case LWS_WS_OPCODE_04__PONG:
fprintf(stderr, "Control frame asking for "
"extended length is illegal\n");
/* kill the connection */
return -1;
default:
break;
}
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_8;
break;
default:
wsi->rx_packet_length = c;
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
break;
}
break;
case LWS_RXPS_04_FRAME_HDR_LEN16_2:
c = wsi->xor_mask(wsi, c);
wsi->rx_packet_length = c << 8;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_1;
break;
case LWS_RXPS_04_FRAME_HDR_LEN16_1:
c = wsi->xor_mask(wsi, c);
wsi->rx_packet_length |= c;
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_8:
c = wsi->xor_mask(wsi, c);
if (c & 0x80) {
fprintf(stderr, "b63 of length must be zero\n");
/* kill the connection */
return -1;
}
#if defined __LP64__
wsi->rx_packet_length = ((size_t)c) << 56;
#else
wsi->rx_packet_length = 0;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_7;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_7:
#if defined __LP64__
wsi->rx_packet_length |= ((size_t)wsi->xor_mask(wsi, c)) << 48;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_6;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_6:
#if defined __LP64__
wsi->rx_packet_length |= ((size_t)wsi->xor_mask(wsi, c)) << 40;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_5;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_5:
#if defined __LP64__
wsi->rx_packet_length |= ((size_t)wsi->xor_mask(wsi, c)) << 32;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_4;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_4:
wsi->rx_packet_length |= ((size_t)wsi->xor_mask(wsi, c)) << 24;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_3;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_3:
wsi->rx_packet_length |= ((size_t)wsi->xor_mask(wsi, c)) << 16;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_2;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_2:
wsi->rx_packet_length |= ((size_t)wsi->xor_mask(wsi, c)) << 8;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_1;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_1:
wsi->rx_packet_length |= ((size_t)wsi->xor_mask(wsi, c));
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
break;
case LWS_RXPS_EAT_UNTIL_76_FF:
if (c == 0xff) {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto issue;
}
wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
(wsi->rx_user_buffer_head++)] = c;
if (wsi->rx_user_buffer_head != MAX_USER_RX_BUFFER)
break;
issue:
if (wsi->protocol->callback)
wsi->protocol->callback(wsi->protocol->owning_server,
wsi, LWS_CALLBACK_RECEIVE,
wsi->user_space,
&wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING],
wsi->rx_user_buffer_head);
wsi->rx_user_buffer_head = 0;
break;
case LWS_RXPS_SEEN_76_FF:
if (c)
break;
debug("Seen that client is requesting "
"a v76 close, sending ack\n");
buf[0] = 0xff;
buf[1] = 0;
n = libwebsocket_write(wsi, buf, 2, LWS_WRITE_HTTP);
if (n < 0) {
fprintf(stderr, "ERROR writing to socket");
return -1;
}
debug(" v76 close ack sent, server closing skt\n");
/* returning < 0 will get it closed in parent */
return -1;
case LWS_RXPS_PULLING_76_LENGTH:
break;
case LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED:
if (wsi->all_zero_nonce && wsi->ietf_spec_revision >= 5)
wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
(wsi->rx_user_buffer_head++)] = c;
else
wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
(wsi->rx_user_buffer_head++)] =
wsi->xor_mask(wsi, c);
if (--wsi->rx_packet_length == 0) {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto spill;
}
if (wsi->rx_user_buffer_head != MAX_USER_RX_BUFFER)
break;
spill:
/*
* is this frame a control packet we should take care of at this
* layer? If so service it and hide it from the user callback
*/
switch (wsi->opcode) {
case LWS_WS_OPCODE_04__CLOSE:
/* parrot the close packet payload back */
n = libwebsocket_write(wsi, (unsigned char *)
&wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING],
wsi->rx_user_buffer_head, LWS_WRITE_CLOSE);
wsi->state = WSI_STATE_RETURNED_CLOSE_ALREADY;
/* close the connection */
return -1;
case LWS_WS_OPCODE_04__PING:
/* parrot the ping packet payload back as a pong */
n = libwebsocket_write(wsi, (unsigned char *)
&wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING],
wsi->rx_user_buffer_head, LWS_WRITE_PONG);
/* ... then just drop it */
wsi->rx_user_buffer_head = 0;
return 0;
case LWS_WS_OPCODE_04__PONG:
/* keep the statistics... */
wsi->pings_vs_pongs--;
/* ... then just drop it */
wsi->rx_user_buffer_head = 0;
return 0;
default:
break;
}
/*
* No it's real payload, pass it up to the user callback.
* It's nicely buffered with the pre-padding taken care of
* so it can be sent straight out again using libwebsocket_write
*/
wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
wsi->rx_user_buffer_head] = '\0';
if (wsi->protocol->callback)
wsi->protocol->callback(wsi->protocol->owning_server,
wsi, LWS_CALLBACK_RECEIVE,
wsi->user_space,
&wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING],
wsi->rx_user_buffer_head);
wsi->rx_user_buffer_head = 0;
break;
}
return 0;
}
int libwebsocket_client_rx_sm(struct libwebsocket *wsi, unsigned char c)
{
int n;
unsigned char buf[20 + 4];
int callback_action = LWS_CALLBACK_CLIENT_RECEIVE;
switch (wsi->lws_rx_parse_state) {
case LWS_RXPS_NEW:
switch (wsi->ietf_spec_revision) {
/* Firefox 4.0b6 likes this as of 30 Oct */
case 0:
if (c == 0xff)
wsi->lws_rx_parse_state = LWS_RXPS_SEEN_76_FF;
if (c == 0) {
wsi->lws_rx_parse_state =
LWS_RXPS_EAT_UNTIL_76_FF;
wsi->rx_user_buffer_head = 0;
}
break;
case 4:
case 5:
case 6:
/*
* 04 logical framing from the spec (all this is masked when
* incoming and has to be unmasked)
*
* We ignore the possibility of extension data because we don't
* negotiate any extensions at the moment.
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-------+-+-------------+-------------------------------+
* |F|R|R|R| opcode|R| Payload len | Extended payload length |
* |I|S|S|S| (4) |S| (7) | (16/63) |
* |N|V|V|V| |V| | (if payload len==126/127) |
* | |1|2|3| |4| | |
* +-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - +
* | Extended payload length continued, if payload len == 127 |
* + - - - - - - - - - - - - - - - +-------------------------------+
* | | Extension data |
* +-------------------------------+ - - - - - - - - - - - - - - - +
* : :
* +---------------------------------------------------------------+
* : Application data :
* +---------------------------------------------------------------+
*
* We pass payload through to userland as soon as we get it, ignoring
* FIN. It's up to userland to buffer it up if it wants to see a
* whole unfragmented block of the original size (which may be up to
* 2^63 long!)
*/
/*
* 04 spec defines the opcode like this: (1, 2, and 3 are
* "control frame" opcodes which may not be fragmented or
* have size larger than 126)
*
* frame-opcode =
* %x0 ; continuation frame
* / %x1 ; connection close
* / %x2 ; ping
* / %x3 ; pong
* / %x4 ; text frame
* / %x5 ; binary frame
* / %x6-F ; reserved
*
* FIN (b7)
*/
if (c & 0x70) {
fprintf(stderr, "Frame has extensions set "
"illegally on first framing byte %02X\n", c);
/* kill the connection */
return -1;
}
wsi->opcode = c & 0xf;
wsi->final = !!((c >> 7) & 1);
if (wsi->final &&
wsi->opcode == LWS_WS_OPCODE_04__CONTINUATION &&
wsi->rx_packet_length == 0) {
fprintf(stderr,
"Frame starts with final continuation\n");
/* kill the connection */
return -1;
}
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN;
break;
default:
fprintf(stderr, "client_rx_sm doesn't know how "
"to handle spec version %02d\n",
wsi->ietf_spec_revision);
break;
}
break;
case LWS_RXPS_04_FRAME_HDR_LEN:
if (c & 0x80) {
fprintf(stderr,
"Frame has extensions set illegally 4\n");
/* kill the connection */
return -1;
}
switch (c) {
case 126:
/* control frames are not allowed to have big lengths */
switch (wsi->opcode) {
case LWS_WS_OPCODE_04__CLOSE:
case LWS_WS_OPCODE_04__PING:
case LWS_WS_OPCODE_04__PONG:
fprintf(stderr, "Control frame asking for "
"extended length is illegal\n");
/* kill the connection */
return -1;
default:
break;
}
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_2;
break;
case 127:
/* control frames are not allowed to have big lengths */
switch (wsi->opcode) {
case LWS_WS_OPCODE_04__CLOSE:
case LWS_WS_OPCODE_04__PING:
case LWS_WS_OPCODE_04__PONG:
fprintf(stderr, "Control frame asking for "
"extended length is illegal\n");
/* kill the connection */
return -1;
default:
break;
}
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_8;
break;
default:
wsi->rx_packet_length = c;
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
break;
}
break;
case LWS_RXPS_04_FRAME_HDR_LEN16_2:
wsi->rx_packet_length = c << 8;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_1;
break;
case LWS_RXPS_04_FRAME_HDR_LEN16_1:
wsi->rx_packet_length |= c;
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_8:
if (c & 0x80) {
fprintf(stderr, "b63 of length must be zero\n");
/* kill the connection */
return -1;
}
#if defined __LP64__
wsi->rx_packet_length = ((size_t)c) << 56;
#else
wsi->rx_packet_length = 0;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_7;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_7:
#if defined __LP64__
wsi->rx_packet_length |= ((size_t)c) << 48;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_6;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_6:
#if defined __LP64__
wsi->rx_packet_length |= ((size_t)c) << 40;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_5;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_5:
#if defined __LP64__
wsi->rx_packet_length |= ((size_t)c) << 32;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_4;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_4:
wsi->rx_packet_length |= ((size_t)c) << 24;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_3;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_3:
wsi->rx_packet_length |= ((size_t)c) << 16;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_2;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_2:
wsi->rx_packet_length |= ((size_t)c) << 8;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_1;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_1:
wsi->rx_packet_length |= (size_t)c;
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
break;
case LWS_RXPS_EAT_UNTIL_76_FF:
if (c == 0xff) {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto issue;
}
wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
(wsi->rx_user_buffer_head++)] = c;
if (wsi->rx_user_buffer_head != MAX_USER_RX_BUFFER)
break;
issue:
if (wsi->protocol->callback)
wsi->protocol->callback(wsi->protocol->owning_server,
wsi,
LWS_CALLBACK_CLIENT_RECEIVE,
wsi->user_space,
&wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING],
wsi->rx_user_buffer_head);
wsi->rx_user_buffer_head = 0;
break;
case LWS_RXPS_SEEN_76_FF:
if (c)
break;
debug("Seen that client is requesting "
"a v76 close, sending ack\n");
buf[0] = 0xff;
buf[1] = 0;
n = libwebsocket_write(wsi, buf, 2, LWS_WRITE_HTTP);
if (n < 0) {
fprintf(stderr, "ERROR writing to socket");
return -1;
}
debug(" v76 close ack sent, server closing skt\n");
/* returning < 0 will get it closed in parent */
return -1;
case LWS_RXPS_PULLING_76_LENGTH:
break;
case LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED:
wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
(wsi->rx_user_buffer_head++)] = c;
if (--wsi->rx_packet_length == 0) {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto spill;
}
if (wsi->rx_user_buffer_head != MAX_USER_RX_BUFFER)
break;
spill:
/*
* is this frame a control packet we should take care of at this
* layer? If so service it and hide it from the user callback
*/
switch (wsi->opcode) {
case LWS_WS_OPCODE_04__CLOSE:
/* parrot the close packet payload back */
n = libwebsocket_write(wsi, (unsigned char *)
&wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING],
wsi->rx_user_buffer_head, LWS_WRITE_CLOSE);
wsi->state = WSI_STATE_RETURNED_CLOSE_ALREADY;
/* close the connection */
return -1;
case LWS_WS_OPCODE_04__PING:
/* parrot the ping packet payload back as a pong*/
n = libwebsocket_write(wsi, (unsigned char *)
&wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING],
wsi->rx_user_buffer_head, LWS_WRITE_PONG);
break;
case LWS_WS_OPCODE_04__PONG:
/* keep the statistics... */
wsi->pings_vs_pongs--;
/* issue it */
callback_action = LWS_CALLBACK_CLIENT_RECEIVE_PONG;
break;
default:
break;
}
/*
* No it's real payload, pass it up to the user callback.
* It's nicely buffered with the pre-padding taken care of
* so it can be sent straight out again using libwebsocket_write
*/
if (wsi->protocol->callback)
wsi->protocol->callback(wsi->protocol->owning_server,
wsi, callback_action,
wsi->user_space,
&wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING],
wsi->rx_user_buffer_head);
wsi->rx_user_buffer_head = 0;
break;
default:
fprintf(stderr, "client rx illegal state\n");
return 1;
}
return 0;
}
int libwebsocket_interpret_incoming_packet(struct libwebsocket *wsi,
unsigned char *buf, size_t len)
{
int n;
#ifdef DEBUG
fprintf(stderr, "received %d byte packet\n", (int)len);
for (n = 0; n < len; n++)
fprintf(stderr, "%02X ", buf[n]);
fprintf(stderr, "\n");
#endif
/* let the rx protocol state machine have as much as it needs */
n = 0;
while (n < len)
if (libwebsocket_rx_sm(wsi, buf[n++]) < 0)
return -1;
return 0;
}
static int
libwebsocket_0405_frame_mask_generate(struct libwebsocket *wsi)
{
char buf[4 + 20];
int n;
/* fetch the per-frame nonce */
n = libwebsockets_get_random(wsi->protocol->owning_server,
wsi->frame_masking_nonce_04, 4);
if (n != 4) {
fprintf(stderr, "Unable to read from random device %s %d\n",
SYSTEM_RANDOM_FILEPATH, n);
return 1;
}
/* start masking from first byte of masking key buffer */
wsi->frame_mask_index = 0;
if (wsi->ietf_spec_revision != 4)
return 0;
/* 04 only does SHA-1 more complex key */
/*
* the frame key is the frame nonce (4 bytes) followed by the
* connection masking key, hashed by SHA1
*/
memcpy(buf, wsi->frame_masking_nonce_04, 4);
memcpy(buf + 4, wsi->masking_key_04, 20);
/* concatenate the nonce with the connection key then hash it */
SHA1((unsigned char *)buf, 4 + 20, wsi->frame_mask_04);
return 0;
}
/**
* libwebsocket_write() - Apply protocol then write data to client
* @wsi: Websocket instance (available from user callback)
* @buf: The data to send. For data being sent on a websocket
* connection (ie, not default http), this buffer MUST have
* LWS_SEND_BUFFER_PRE_PADDING bytes valid BEFORE the pointer
* and an additional LWS_SEND_BUFFER_POST_PADDING bytes valid
* in the buffer after (buf + len). This is so the protocol
* header and trailer data can be added in-situ.
* @len: Count of the data bytes in the payload starting from buf
* @protocol: Use LWS_WRITE_HTTP to reply to an http connection, and one
* of LWS_WRITE_BINARY or LWS_WRITE_TEXT to send appropriate
* data on a websockets connection. Remember to allow the extra
* bytes before and after buf if LWS_WRITE_BINARY or LWS_WRITE_TEXT
* are used.
*
* This function provides the way to issue data back to the client
* for both http and websocket protocols.
*
* In the case of sending using websocket protocol, be sure to allocate
* valid storage before and after buf as explained above. This scheme
* allows maximum efficiency of sending data and protocol in a single
* packet while not burdening the user code with any protocol knowledge.
*/
int libwebsocket_write(struct libwebsocket *wsi, unsigned char *buf,
size_t len, enum libwebsocket_write_protocol protocol)
{
int n;
int pre = 0;
int post = 0;
unsigned int shift = 7;
if (len == 0 && protocol != LWS_WRITE_CLOSE) {
fprintf(stderr, "zero length libwebsocket_write attempt\n");
return 0;
}
if (protocol == LWS_WRITE_HTTP)
goto send_raw;
/* websocket protocol, either binary or text */
if (wsi->state != WSI_STATE_ESTABLISHED)
return -1;
switch (wsi->ietf_spec_revision) {
/* chrome likes this as of 30 Oct */
/* Firefox 4.0b6 likes this as of 30 Oct */
case 0:
if ((protocol & 0xf) == LWS_WRITE_BINARY) {
/* in binary mode we send 7-bit used length blocks */
pre = 1;
while (len & (127 << shift)) {
pre++;
shift += 7;
}
n = 0;
shift -= 7;
while (shift >= 0) {
if (shift)
buf[0 - pre + n] =
((len >> shift) & 127) | 0x80;
else
buf[0 - pre + n] =
((len >> shift) & 127);
n++;
shift -= 7;
}
break;
}
/* frame type = text, length-free spam mode */
buf[-1] = 0;
buf[len] = 0xff; /* EOT marker */
pre = 1;
post = 1;
break;
case 4:
case 5:
case 6:
switch (protocol & 0xf) {
case LWS_WRITE_TEXT:
n = LWS_WS_OPCODE_04__TEXT_FRAME;
break;
case LWS_WRITE_BINARY:
n = LWS_WS_OPCODE_04__BINARY_FRAME;
break;
case LWS_WRITE_CLOSE:
n = LWS_WS_OPCODE_04__CLOSE;
/*
* v5 mandates the first byte of close packet
* in both client and server directions
*/
switch (wsi->ietf_spec_revision) {
case 0:
case 4:
break;
case 5:
/* we can do this because we demand post-buf */
if (len < 1)
len = 1;
switch (wsi->mode) {
case LWS_CONNMODE_WS_SERVING:
/*
fprintf(stderr, "LWS_WRITE_CLOSE S\n");
*/
buf[0] = 'S';
break;
case LWS_CONNMODE_WS_CLIENT:
/*
fprintf(stderr, "LWS_WRITE_CLOSE C\n");
*/
buf[0] = 'C';
break;
default:
break;
}
break;
default:
/*
* 06 has a 2-byte status code in network order
* we can do this because we demand post-buf
*/
if (wsi->close_reason) {
buf[pre - 2] = wsi->close_reason >> 8;
buf[pre - 1] = wsi->close_reason;
pre += 2;
}
break;
}
break;
case LWS_WRITE_PING:
n = LWS_WS_OPCODE_04__PING;
wsi->pings_vs_pongs++;
break;
case LWS_WRITE_PONG:
n = LWS_WS_OPCODE_04__PONG;
break;
default:
fprintf(stderr, "libwebsocket_write: unknown write "
"opcode / protocol\n");
return -1;
}
if (!(protocol & LWS_WRITE_NO_FIN))
n |= 1 << 7;
if (len < 126) {
buf[pre - 2] = n;
buf[pre - 1] = len;
pre += 2;
} else {
if (len < 65536) {
buf[pre - 4] = n;
buf[pre - 3] = 126;
buf[pre - 2] = len >> 8;
buf[pre - 1] = len;
pre += 4;
} else {
buf[pre - 10] = n;
buf[pre - 9] = 127;
#if defined __LP64__
buf[pre - 8] = (len >> 56) & 0x7f;
buf[pre - 7] = len >> 48;
buf[pre - 6] = len >> 40;
buf[pre - 5] = len >> 32;
#else
buf[pre - 8] = 0;
buf[pre - 7] = 0;
buf[pre - 6] = 0;
buf[pre - 5] = 0;
#endif
buf[pre - 4] = len >> 24;
buf[pre - 3] = len >> 16;
buf[pre - 2] = len >> 8;
buf[pre - 1] = len;
pre += 10;
}
}
break;
}
#if 0
for (n = 0; n < (len + pre + post); n++)
fprintf(stderr, "%02X ", buf[n - pre]);
fprintf(stderr, "\n");
#endif
/*
* Deal with masking if we are in client -> server direction and
* the protocol demands it
*/
if (wsi->mode == LWS_CONNMODE_WS_CLIENT &&
wsi->ietf_spec_revision >= 4) {
/*
* this is only useful for security tests where it's required
* to control the raw packet payload content
*/
if (!(protocol & LWS_WRITE_CLIENT_IGNORE_XOR_MASK)) {
if (libwebsocket_0405_frame_mask_generate(wsi)) {
fprintf(stderr, "libwebsocket_write: "
"frame mask generation failed\n");
return 1;
}
/*
* use the XOR masking against everything we send
* past the frame nonce
*/
for (n = 0; n < (len + pre + post); n++)
buf[n - pre] = wsi->xor_mask(wsi, buf[n - pre]);
/* make space for the frame nonce in clear */
pre += 4;
/* copy the frame nonce into place */
memcpy(&buf[0 - pre], wsi->frame_masking_nonce_04, 4);
} else {
/* make space for the frame nonce in clear */
pre += 4;
buf[0 - pre] = 0;
buf[1 - pre] = 0;
buf[2 - pre] = 0;
buf[3 - pre] = 0;
}
}
send_raw:
#ifdef LWS_OPENSSL_SUPPORT
if (wsi->ssl) {
n = SSL_write(wsi->ssl, buf - pre, len + pre + post);
if (n < 0) {
fprintf(stderr, "ERROR writing to socket\n");
return -1;
}
} else {
#endif
n = send(wsi->sock, buf - pre, len + pre + post, MSG_NOSIGNAL);
if (n < 0) {
fprintf(stderr, "ERROR writing to socket\n");
return -1;
}
#ifdef LWS_OPENSSL_SUPPORT
}
#endif
debug("written %d bytes to client\n", (int)len);
return 0;
}
/**
* libwebsockets_serve_http_file() - Send a file back to the client using http
* @wsi: Websocket instance (available from user callback)
* @file: The file to issue over http
* @content_type: The http content type, eg, text/html
*
* This function is intended to be called from the callback in response
* to http requests from the client. It allows the callback to issue
* local files down the http link in a single step.
*/
int libwebsockets_serve_http_file(struct libwebsocket *wsi, const char *file,
const char *content_type)
{
int fd;
struct stat stat_buf;
char buf[512];
char *p = buf;
int n;
fd = open(file, O_RDONLY);
if (fd < 1) {
p += sprintf(p, "HTTP/1.0 400 Bad\x0d\x0a"
"Server: libwebsockets\x0d\x0a"
"\x0d\x0a"
);
libwebsocket_write(wsi, (unsigned char *)buf, p - buf,
LWS_WRITE_HTTP);
return -1;
}
fstat(fd, &stat_buf);
p += sprintf(p, "HTTP/1.0 200 OK\x0d\x0a"
"Server: libwebsockets\x0d\x0a"
"Content-Type: %s\x0d\x0a"
"Content-Length: %u\x0d\x0a"
"\x0d\x0a", content_type, (unsigned int)stat_buf.st_size);
libwebsocket_write(wsi, (unsigned char *)buf, p - buf, LWS_WRITE_HTTP);
n = 1;
while (n > 0) {
n = read(fd, buf, 512);
if (n <= 0)
continue;
libwebsocket_write(wsi, (unsigned char *)buf, n,
LWS_WRITE_HTTP);
}
close(fd);
return 0;
}
/**
* libwebsockets_remaining_packet_payload() - Bytes to come before "overall"
* rx packet is complete
* @wsi: Websocket instance (available from user callback)
*
* This function is intended to be called from the callback if the
* user code is interested in "complete packets" from the client.
* libwebsockets just passes through payload as it comes and issues a buffer
* additionally when it hits a built-in limit. The LWS_CALLBACK_RECEIVE
* callback handler can use this API to find out if the buffer it has just
* been given is the last piece of a "complete packet" from the client --
* when that is the case libwebsockets_remaining_packet_payload() will return
* 0.
*
* Many protocols won't care becuse their packets are always small.
*/
size_t
libwebsockets_remaining_packet_payload(struct libwebsocket *wsi)
{
return wsi->rx_packet_length;
}
Reference in a new issue View git blame Copy permalink